This invention relates to axial piston hydraulic machines. More specifically, this invention relates to an axial piston hydraulic machine having a ball supported swashplate.
Many existing motor/gearbox combinations for track drives on construction equipment utilize an axial piston hydraulic machine having a swashplate which pivots on two balls located in ball sockets in the back of the swashplate and in the supporting housing. These designs place the support balls directly behind the piston running surface of the swashplate. Consequently, the swashplate pivot axis, is a significant distance behind the plane passing through the centers of the piston/slipper ball joints. When the pivot axis of the swashplate is not near the plane passing through the centers of the piston/slipper ball joints, the moments on the swashplate can vary significantly, making it difficult to control the position of the swashplate. Specifically, in intermediate positions there is a wide variation in swashplate moments due to varying pressure and speeds. Similarly, the variation between pumping and motoring modes causes significant swashplate moments.
Therefore, a principal object of the present invention is to provide an axial piston pump that allows for enhanced control of the swashplate.
Yet another object of the present invention is to minimize the variability of the moments on the swashplate.
Another object of the present invention is to reduce the axial length of a motor or a gearbox package.
These and other objects, features, or advantages of the present invention will become apparent from the specification and claims.